Expiration behaviour, roles and capabilities

Hello PMPRO devs,
I have some issues puzzling me and I hope you can help in understanding your plugin behaviour a little better.

I have PMPRO and PMPRO and PMPRO Roles installed (your plugin came with a theme and we’re evaluating whether to stick to it and buy your support membership) and when a member buys any membership he is granted the corresponding role in addition to his original one. So far so good.

-What happens however when a membership expires? Are members rolled back to their original role either the only effect is that they just lose access to membership restricted posts/pages while keeping other membership-role capabilities? (I tried to manually set some memberships from wp-admin to a past date, but nothing happened: membership was expired but user was not deprived of any membership-role-based capability).

-could you please be so kind to point me to the appropriate file for modifying the text and /or disable the default 7 days expiration notice?

Very many thanks in advance for your support.

https://wordpress.org/plugins/paid-memberships-pro/